Accupro T1634563 Spiral Flute Tap 1/2-13 3 Flute Hss

Product Description

The ACCUPRO T1634563 is a spiral flute tap designed for threading 1/2-13 holes in a wide range of ferrous and non-ferrous materials. It features three right-hand flutes with a 33-degree helix angle, which helps evacuate chips upward out of the hole — a key advantage when tapping blind holes. The modified bottoming chamfer allows threading close to the bottom of a hole without the runout of a standard plug or taper tap. Built from vanadium high speed steel with an oxide finish, this tap offers solid wear resistance and lubrication retention for production and repair threading work. It is sized to produce a 3B class of fit with an H3 thread limit.

This tap is used in machining, maintenance, and fabrication environments where 1/2-13 UNC internal threads are required. The modified bottoming style makes it well suited for blind-hole applications in manual machining and CNC setups alike. Machinists, toolmakers, and maintenance mechanics commonly reach for this tap when threading steel, cast iron, aluminum, and similar materials. The right-hand thread and right-hand flute direction are standard for conventional tapping operations. Coolant-through capability is not included, so external cutting fluid application is recommended for extended production runs.

Key Features

• 1/2-13 UNC thread size with H3 thread limit for consistent 3B class of fit tolerances
• Modified bottoming chamfer for threading close to the bottom of blind holes
• 33-degree helix angle spiral flutes promote upward chip evacuation in blind-hole tapping
• Vanadium high speed steel construction for improved wear resistance over standard HSS
• Oxide finish aids lubrication retention and provides mild corrosion resistance during storage and use
• Right-hand thread and right-hand flute direction for standard tapping operations

Compatibility

Designed as a standard 1/2-13 UNC spiral flute tap compatible with conventional tap holders, tapping chucks, and CNC rigid tapping setups that accept the 0.367-inch shank diameter.

Installation Notes

Installation should be performed by a qualified machinist or maintenance mechanic familiar with proper tapping procedures. Ensure the workpiece is securely fixtured and the tap is properly aligned with the drilled pilot hole before engagement. Apply an appropriate cutting fluid or tapping compound throughout the operation to extend tool life and improve thread quality. Do not force the tap if resistance increases unexpectedly — back off to break and clear chips before continuing.